The present invention relates to an optical substrate, and a manufacturing method and display-device for the same.
A method for filling the depressions in a light transmitting layer with pigment has been developed as a method of manufacturing color filters for use with, for example, liquid crystal display panels. The light transmitting layer used in this process can be easily manufactured by dripping resin onto a master having a surface pattern of depressions and protrusions, curing the resin, and then separating the patterned resin from the master.
As a method for manufacturing a microlens array for use with such products as liquid crystal display panels, Japanese Unexamined Patent Application (kokai) 3-198003 teaches a method for manufacturing a microlens array by dripping resin onto a master having a plurality of curved surfaces corresponding to lenses, curing the resin to form a light transmitting layer, and then separating this light transmitting layer to produce the microlens array.
With these methods, however, it is necessary to separately manufacture and then combine the color filter and microlens array.
The present invention resolves this problem by providing a method for easily manufacturing an optical substrate whereby a bright color display can be achieved, an optical substrate manufactured by this method, and a display device that uses the optical substrate.
(1) A manufacturing method for an optical substrate according to the present invention comprises:
a step for forming a light transmitting layer by bonding a first master having a plurality of color protrusions with a second master having a plurality of curved surface parts with a light transmitting layer precursor disposed therebetween so as to form a light transmitting layer having a plurality of color recesses transferred from the color protrusions and a plurality of lenses transferred from the curved surface parts;
a step for separating the first master from the light transmitting layer;
a step for forming a color pattern layer by filling the color recesses in the light transmitting layer with pigment; and
a step for separating the second master from the light transmitting layer.
This method of the invention uses the color protrusions of the first master as a die for molding color recesses in the light transmitting layer. Then, using the curved surface parts of the second master, lenses are molded on the side opposite the color recesses. Finally, the color recesses are filled with pigment to form a color pattern layer. An optical substrate of which one surface functions as a microlens array and the other surface functions as a color filter is thus achieved.
Because the pigment is only filled to the color recesses and it is not necessary to separate the pigment from the master, the pigment is not deformed and voids do not occur. Furthermore, because the masters can be used repeatedly insofar as durability allows once manufactured, the steps required to produce the masters can be eliminated from the production process for the second and subsequent optical substrates, thereby further reducing the number of production steps and helping to further reduce cost.
(2) In the method described in (1) above, the step for forming the light transmitting layer can bond the first and second masters with the color protrusions of the first master opposite the curved surface parts of the second master. This assures that light gathered by each lens passes each pixel of the color filter.
(3) A further manufacturing method for an optical substrate according to the present invention comprises:
a step for forming a color pattern layer by filling the color recesses in a first master having a plurality of color recesses with pigment;
a step for forming a light transmitting layer by bonding the first master to a second master having a plurality of curved surface parts with a light transmitting layer precursor disposed therebetween so as to form a light transmitting layer bonded with the color pattern layer and having a plurality of lenses transferred from the shape of the curved surface parts;
a step for separating the first master from the light transmitting layer and color pattern layer; and
a step for separating the second master from the light transmitting layer.
In this second method of the invention a color pattern layer is formed by filling color recesses in the first master with pigment. The color pattern layer is then integrated with a light transmitting layer. Lenses are integrally molded to the light transmitting layer using the curved surface parts of the second master as a die. An optical substrate of which one surface functions as a microlens array and the other surface functions as a color filter is thus achieved.
Once manufactured, the masters can be used repeatedly insofar as durability allows. The steps required to produce the masters can therefore be eliminated from the production process for the second and subsequent optical substrates, thereby further reducing the number of production steps and helping to further reduce cost.
In the third method described above, the step for forming the light transmitting layer can bond the first and second masters with the color recesses of the first master opposite the curved surface parts of the second master. This assures that light gathered by each of the lenses passes each of the pixels of the color filter.
(5) The first to fourth methods of the invention described above can further have:
a first step for forming a second light transmitting layer by bonding the light transmitting layer and a third master having a light blocking protrusion dividing a plurality of areas with a second light transmitting layer precursor disposed therebetween so as to form a second light transmitting layer having a light blocking recess transferred from the shape of the light blocking protrusion;
a second step for separating the third master from the second light transmitting layer; and
a third step for filling the light blocking recess with a light blocking material.
In this method a light blocking recess is formed in the second light transmitting layer using the light blocking protrusion of the third master as a die. A light blocking layer is then formed by filling the light blocking recess with a light blocking material. The resulting light blocking layer forms a black matrix.
Because the light blocking material is simply filled to the light blocking recess and it is not necessary to remove the light blocking material from the master, it is not deformed and voids do not occur therein.
Furthermore, once manufactured, the third master can also be used repeatedly insofar as durability allows. The steps required to produce the master can therefore be eliminated from the production process for the second and subsequent optical substrates, thereby further reducing the number of production steps and helping to further reduce cost.
(6) In the fifth method described above the first step preferably aligns the light blocking protrusion of the third master to a position at which each of the lenses of the light transmitting layer is enclosed. This assures that light gathered by each lens passes each pixel of the color filter divided by the black matrix.
(7) The first to -fourth methods described above further preferably have the following steps:
a first step for forming a light blocking layer by filling a light blocking recess part of a third master having a light blocking recess dividing a plurality of areas with a light blocking material;
a second step for forming a second light transmitting layer bonded to said light blocking layer by bonding said light transmitting layer and third master with a second light transmitting layer precursor disposed therebetween; and
a third step for separating the third master from the second light transmitting layer and light blocking layer.
With this method the light blocking layer formed in the light blocking recess of the third master forms a black matrix integrated with the second light transmitting layer.
Furthermore, once manufactured, the third master can be used repeatedly insofar as durability allows. The steps required to produce the master can therefore be eliminated from the production process for the second and subsequent optical substrates, thereby further reducing the number of production steps and helping to further reduce cost.
(8) In the seventh method described above the second step preferably aligns the light blocking recess of the third master so that the lenses of the light transmitting layer are each enclosed when bonding the light transmitting layer to the third master. This assures that light gathered by each of the lenses passes each of the pixels of the color filter divided by the black matrix.
(9) The present invention also provides an optical substrate manufactured using any of the above methods.
(10) An optical substrate according to the present invention comprises: a light transmitting layer having a plurality of color recesses on one side and a plurality of lenses on an other side with the lenses formed at positions corresponding to the color recesses; and a color pattern layer formed by filling said color recesses with pigment.
One side of this optical substrate can thus function as a microlens array while the other side functions as a color filter.
(11) An optical substrate according to the present invention has a light transmitting layer with a plurality of lenses formed on one side, and a color pattern layer integrally formed to the other side of the light transmitting layer.
One side of -this optical substrate can thus function as a microlens array while the other side functions as a color filter.
(12) An optical substrate as noted in (10) or (11) above further preferably has a second light transmitting layer formed on said light transmitting layer with a light blocking recess; and a light blocking layer formed by filling said light blocking recess with a light blocking material.
In this optical substrate the light blocking layer functions as a black matrix.
(13) An optical substrate as noted in (10) or (11) above alternatively has a second light transmitting layer formed on the light transmitting layer; and a light blocking layer formed on the second light transmitting layer.
The light blocking layer of this optical substrate functions as a black matrix.
(14) The optical substrate in (12) or (13) above preferably has the light blocking layer formed so that each lens is enclosed in one of the plurality of areas of the light blocking layer.
(15) A display device according to the present invention comprises an optical substrate as noted in any of (9) to (14) above, and a light source for emitting light to the optical substrate.